EL4121 Embedded System / mbed-os

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features/mbedtls/src/entropy_poll.c@0:b74591d5ab33, 2017-12-11 (annotated)

Committer:
be_bryan
Date:
Mon Dec 11 17:54:04 2017 +0000
Revision:
0:b74591d5ab33
motor ++

Who changed what in which revision?

UserRevisionLine numberNew contents of line
be_bryan 0:b74591d5ab33 1 /*
be_bryan 0:b74591d5ab33 2 * Platform-specific and custom entropy polling functions
be_bryan 0:b74591d5ab33 3 *
be_bryan 0:b74591d5ab33 4 * Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
be_bryan 0:b74591d5ab33 5 * SPDX-License-Identifier: Apache-2.0
be_bryan 0:b74591d5ab33 6 *
be_bryan 0:b74591d5ab33 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
be_bryan 0:b74591d5ab33 8 * not use this file except in compliance with the License.
be_bryan 0:b74591d5ab33 9 * You may obtain a copy of the License at
be_bryan 0:b74591d5ab33 10 *
be_bryan 0:b74591d5ab33 11 * http://www.apache.org/licenses/LICENSE-2.0
be_bryan 0:b74591d5ab33 12 *
be_bryan 0:b74591d5ab33 13 * Unless required by applicable law or agreed to in writing, software
be_bryan 0:b74591d5ab33 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
be_bryan 0:b74591d5ab33 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
be_bryan 0:b74591d5ab33 16 * See the License for the specific language governing permissions and
be_bryan 0:b74591d5ab33 17 * limitations under the License.
be_bryan 0:b74591d5ab33 18 *
be_bryan 0:b74591d5ab33 19 * This file is part of mbed TLS (https://tls.mbed.org)
be_bryan 0:b74591d5ab33 20 */
be_bryan 0:b74591d5ab33 21
be_bryan 0:b74591d5ab33 22 #if !defined(MBEDTLS_CONFIG_FILE)
be_bryan 0:b74591d5ab33 23 #include "mbedtls/config.h"
be_bryan 0:b74591d5ab33 24 #else
be_bryan 0:b74591d5ab33 25 #include MBEDTLS_CONFIG_FILE
be_bryan 0:b74591d5ab33 26 #endif
be_bryan 0:b74591d5ab33 27
be_bryan 0:b74591d5ab33 28 #if defined(MBEDTLS_ENTROPY_C)
be_bryan 0:b74591d5ab33 29
be_bryan 0:b74591d5ab33 30 #include "mbedtls/entropy.h"
be_bryan 0:b74591d5ab33 31 #include "mbedtls/entropy_poll.h"
be_bryan 0:b74591d5ab33 32
be_bryan 0:b74591d5ab33 33 #if defined(MBEDTLS_TIMING_C)
be_bryan 0:b74591d5ab33 34 #include <string.h>
be_bryan 0:b74591d5ab33 35 #include "mbedtls/timing.h"
be_bryan 0:b74591d5ab33 36 #endif
be_bryan 0:b74591d5ab33 37 #if defined(MBEDTLS_HAVEGE_C)
be_bryan 0:b74591d5ab33 38 #include "mbedtls/havege.h"
be_bryan 0:b74591d5ab33 39 #endif
be_bryan 0:b74591d5ab33 40 #if defined(MBEDTLS_ENTROPY_NV_SEED)
be_bryan 0:b74591d5ab33 41 #include "mbedtls/platform.h"
be_bryan 0:b74591d5ab33 42 #endif
be_bryan 0:b74591d5ab33 43
be_bryan 0:b74591d5ab33 44 #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
be_bryan 0:b74591d5ab33 45
be_bryan 0:b74591d5ab33 46 #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
be_bryan 0:b74591d5ab33 47 !defined(__APPLE__) && !defined(_WIN32)
be_bryan 0:b74591d5ab33 48 #error "Platform entropy sources only work on Unix and Windows, see MBEDTLS_NO_PLATFORM_ENTROPY in config.h"
be_bryan 0:b74591d5ab33 49 #endif
be_bryan 0:b74591d5ab33 50
be_bryan 0:b74591d5ab33 51 #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
be_bryan 0:b74591d5ab33 52
be_bryan 0:b74591d5ab33 53 #if !defined(_WIN32_WINNT)
be_bryan 0:b74591d5ab33 54 #define _WIN32_WINNT 0x0400
be_bryan 0:b74591d5ab33 55 #endif
be_bryan 0:b74591d5ab33 56 #include <windows.h>
be_bryan 0:b74591d5ab33 57 #include <wincrypt.h>
be_bryan 0:b74591d5ab33 58
be_bryan 0:b74591d5ab33 59 int mbedtls_platform_entropy_poll( void *data, unsigned char *output, size_t len,
be_bryan 0:b74591d5ab33 60 size_t *olen )
be_bryan 0:b74591d5ab33 61 {
be_bryan 0:b74591d5ab33 62 HCRYPTPROV provider;
be_bryan 0:b74591d5ab33 63 ((void) data);
be_bryan 0:b74591d5ab33 64 *olen = 0;
be_bryan 0:b74591d5ab33 65
be_bryan 0:b74591d5ab33 66 if( CryptAcquireContext( &provider, NULL, NULL,
be_bryan 0:b74591d5ab33 67 PROV_RSA_FULL, CRYPT_VERIFYCONTEXT ) == FALSE )
be_bryan 0:b74591d5ab33 68 {
be_bryan 0:b74591d5ab33 69 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
be_bryan 0:b74591d5ab33 70 }
be_bryan 0:b74591d5ab33 71
be_bryan 0:b74591d5ab33 72 if( CryptGenRandom( provider, (DWORD) len, output ) == FALSE )
be_bryan 0:b74591d5ab33 73 {
be_bryan 0:b74591d5ab33 74 CryptReleaseContext( provider, 0 );
be_bryan 0:b74591d5ab33 75 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
be_bryan 0:b74591d5ab33 76 }
be_bryan 0:b74591d5ab33 77
be_bryan 0:b74591d5ab33 78 CryptReleaseContext( provider, 0 );
be_bryan 0:b74591d5ab33 79 *olen = len;
be_bryan 0:b74591d5ab33 80
be_bryan 0:b74591d5ab33 81 return( 0 );
be_bryan 0:b74591d5ab33 82 }
be_bryan 0:b74591d5ab33 83 #else /* _WIN32 && !EFIX64 && !EFI32 */
be_bryan 0:b74591d5ab33 84
be_bryan 0:b74591d5ab33 85 /*
be_bryan 0:b74591d5ab33 86 * Test for Linux getrandom() support.
be_bryan 0:b74591d5ab33 87 * Since there is no wrapper in the libc yet, use the generic syscall wrapper
be_bryan 0:b74591d5ab33 88 * available in GNU libc and compatible libc's (eg uClibc).
be_bryan 0:b74591d5ab33 89 */
be_bryan 0:b74591d5ab33 90 #if defined(__linux__) && defined(__GLIBC__)
be_bryan 0:b74591d5ab33 91 #include <unistd.h>
be_bryan 0:b74591d5ab33 92 #include <sys/syscall.h>
be_bryan 0:b74591d5ab33 93 #if defined(SYS_getrandom)
be_bryan 0:b74591d5ab33 94 #define HAVE_GETRANDOM
be_bryan 0:b74591d5ab33 95
be_bryan 0:b74591d5ab33 96 static int getrandom_wrapper( void *buf, size_t buflen, unsigned int flags )
be_bryan 0:b74591d5ab33 97 {
be_bryan 0:b74591d5ab33 98 /* MemSan cannot understand that the syscall writes to the buffer */
be_bryan 0:b74591d5ab33 99 #if defined(__has_feature)
be_bryan 0:b74591d5ab33 100 #if __has_feature(memory_sanitizer)
be_bryan 0:b74591d5ab33 101 memset( buf, 0, buflen );
be_bryan 0:b74591d5ab33 102 #endif
be_bryan 0:b74591d5ab33 103 #endif
be_bryan 0:b74591d5ab33 104
be_bryan 0:b74591d5ab33 105 return( syscall( SYS_getrandom, buf, buflen, flags ) );
be_bryan 0:b74591d5ab33 106 }
be_bryan 0:b74591d5ab33 107
be_bryan 0:b74591d5ab33 108 #include <sys/utsname.h>
be_bryan 0:b74591d5ab33 109 /* Check if version is at least 3.17.0 */
be_bryan 0:b74591d5ab33 110 static int check_version_3_17_plus( void )
be_bryan 0:b74591d5ab33 111 {
be_bryan 0:b74591d5ab33 112 int minor;
be_bryan 0:b74591d5ab33 113 struct utsname un;
be_bryan 0:b74591d5ab33 114 const char *ver;
be_bryan 0:b74591d5ab33 115
be_bryan 0:b74591d5ab33 116 /* Get version information */
be_bryan 0:b74591d5ab33 117 uname(&un);
be_bryan 0:b74591d5ab33 118 ver = un.release;
be_bryan 0:b74591d5ab33 119
be_bryan 0:b74591d5ab33 120 /* Check major version; assume a single digit */
be_bryan 0:b74591d5ab33 121 if( ver[0] < '3' || ver[0] > '9' || ver [1] != '.' )
be_bryan 0:b74591d5ab33 122 return( -1 );
be_bryan 0:b74591d5ab33 123
be_bryan 0:b74591d5ab33 124 if( ver[0] - '0' > 3 )
be_bryan 0:b74591d5ab33 125 return( 0 );
be_bryan 0:b74591d5ab33 126
be_bryan 0:b74591d5ab33 127 /* Ok, so now we know major == 3, check minor.
be_bryan 0:b74591d5ab33 128 * Assume 1 or 2 digits. */
be_bryan 0:b74591d5ab33 129 if( ver[2] < '0' || ver[2] > '9' )
be_bryan 0:b74591d5ab33 130 return( -1 );
be_bryan 0:b74591d5ab33 131
be_bryan 0:b74591d5ab33 132 minor = ver[2] - '0';
be_bryan 0:b74591d5ab33 133
be_bryan 0:b74591d5ab33 134 if( ver[3] >= '0' && ver[3] <= '9' )
be_bryan 0:b74591d5ab33 135 minor = 10 * minor + ver[3] - '0';
be_bryan 0:b74591d5ab33 136 else if( ver [3] != '.' )
be_bryan 0:b74591d5ab33 137 return( -1 );
be_bryan 0:b74591d5ab33 138
be_bryan 0:b74591d5ab33 139 if( minor < 17 )
be_bryan 0:b74591d5ab33 140 return( -1 );
be_bryan 0:b74591d5ab33 141
be_bryan 0:b74591d5ab33 142 return( 0 );
be_bryan 0:b74591d5ab33 143 }
be_bryan 0:b74591d5ab33 144 static int has_getrandom = -1;
be_bryan 0:b74591d5ab33 145 #endif /* SYS_getrandom */
be_bryan 0:b74591d5ab33 146 #endif /* __linux__ */
be_bryan 0:b74591d5ab33 147
be_bryan 0:b74591d5ab33 148 #include <stdio.h>
be_bryan 0:b74591d5ab33 149
be_bryan 0:b74591d5ab33 150 int mbedtls_platform_entropy_poll( void *data,
be_bryan 0:b74591d5ab33 151 unsigned char *output, size_t len, size_t *olen )
be_bryan 0:b74591d5ab33 152 {
be_bryan 0:b74591d5ab33 153 FILE *file;
be_bryan 0:b74591d5ab33 154 size_t read_len;
be_bryan 0:b74591d5ab33 155 ((void) data);
be_bryan 0:b74591d5ab33 156
be_bryan 0:b74591d5ab33 157 #if defined(HAVE_GETRANDOM)
be_bryan 0:b74591d5ab33 158 if( has_getrandom == -1 )
be_bryan 0:b74591d5ab33 159 has_getrandom = ( check_version_3_17_plus() == 0 );
be_bryan 0:b74591d5ab33 160
be_bryan 0:b74591d5ab33 161 if( has_getrandom )
be_bryan 0:b74591d5ab33 162 {
be_bryan 0:b74591d5ab33 163 int ret;
be_bryan 0:b74591d5ab33 164
be_bryan 0:b74591d5ab33 165 if( ( ret = getrandom_wrapper( output, len, 0 ) ) < 0 )
be_bryan 0:b74591d5ab33 166 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
be_bryan 0:b74591d5ab33 167
be_bryan 0:b74591d5ab33 168 *olen = ret;
be_bryan 0:b74591d5ab33 169 return( 0 );
be_bryan 0:b74591d5ab33 170 }
be_bryan 0:b74591d5ab33 171 #endif /* HAVE_GETRANDOM */
be_bryan 0:b74591d5ab33 172
be_bryan 0:b74591d5ab33 173 *olen = 0;
be_bryan 0:b74591d5ab33 174
be_bryan 0:b74591d5ab33 175 file = fopen( "/dev/urandom", "rb" );
be_bryan 0:b74591d5ab33 176 if( file == NULL )
be_bryan 0:b74591d5ab33 177 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
be_bryan 0:b74591d5ab33 178
be_bryan 0:b74591d5ab33 179 read_len = fread( output, 1, len, file );
be_bryan 0:b74591d5ab33 180 if( read_len != len )
be_bryan 0:b74591d5ab33 181 {
be_bryan 0:b74591d5ab33 182 fclose( file );
be_bryan 0:b74591d5ab33 183 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
be_bryan 0:b74591d5ab33 184 }
be_bryan 0:b74591d5ab33 185
be_bryan 0:b74591d5ab33 186 fclose( file );
be_bryan 0:b74591d5ab33 187 *olen = len;
be_bryan 0:b74591d5ab33 188
be_bryan 0:b74591d5ab33 189 return( 0 );
be_bryan 0:b74591d5ab33 190 }
be_bryan 0:b74591d5ab33 191 #endif /* _WIN32 && !EFIX64 && !EFI32 */
be_bryan 0:b74591d5ab33 192 #endif /* !MBEDTLS_NO_PLATFORM_ENTROPY */
be_bryan 0:b74591d5ab33 193
be_bryan 0:b74591d5ab33 194 #if defined(MBEDTLS_TEST_NULL_ENTROPY)
be_bryan 0:b74591d5ab33 195 int mbedtls_null_entropy_poll( void *data,
be_bryan 0:b74591d5ab33 196 unsigned char *output, size_t len, size_t *olen )
be_bryan 0:b74591d5ab33 197 {
be_bryan 0:b74591d5ab33 198 ((void) data);
be_bryan 0:b74591d5ab33 199 ((void) output);
be_bryan 0:b74591d5ab33 200 *olen = 0;
be_bryan 0:b74591d5ab33 201
be_bryan 0:b74591d5ab33 202 if( len < sizeof(unsigned char) )
be_bryan 0:b74591d5ab33 203 return( 0 );
be_bryan 0:b74591d5ab33 204
be_bryan 0:b74591d5ab33 205 *olen = sizeof(unsigned char);
be_bryan 0:b74591d5ab33 206
be_bryan 0:b74591d5ab33 207 return( 0 );
be_bryan 0:b74591d5ab33 208 }
be_bryan 0:b74591d5ab33 209 #endif
be_bryan 0:b74591d5ab33 210
be_bryan 0:b74591d5ab33 211 #if defined(MBEDTLS_TIMING_C)
be_bryan 0:b74591d5ab33 212 int mbedtls_hardclock_poll( void *data,
be_bryan 0:b74591d5ab33 213 unsigned char *output, size_t len, size_t *olen )
be_bryan 0:b74591d5ab33 214 {
be_bryan 0:b74591d5ab33 215 unsigned long timer = mbedtls_timing_hardclock();
be_bryan 0:b74591d5ab33 216 ((void) data);
be_bryan 0:b74591d5ab33 217 *olen = 0;
be_bryan 0:b74591d5ab33 218
be_bryan 0:b74591d5ab33 219 if( len < sizeof(unsigned long) )
be_bryan 0:b74591d5ab33 220 return( 0 );
be_bryan 0:b74591d5ab33 221
be_bryan 0:b74591d5ab33 222 memcpy( output, &timer, sizeof(unsigned long) );
be_bryan 0:b74591d5ab33 223 *olen = sizeof(unsigned long);
be_bryan 0:b74591d5ab33 224
be_bryan 0:b74591d5ab33 225 return( 0 );
be_bryan 0:b74591d5ab33 226 }
be_bryan 0:b74591d5ab33 227 #endif /* MBEDTLS_TIMING_C */
be_bryan 0:b74591d5ab33 228
be_bryan 0:b74591d5ab33 229 #if defined(MBEDTLS_HAVEGE_C)
be_bryan 0:b74591d5ab33 230 int mbedtls_havege_poll( void *data,
be_bryan 0:b74591d5ab33 231 unsigned char *output, size_t len, size_t *olen )
be_bryan 0:b74591d5ab33 232 {
be_bryan 0:b74591d5ab33 233 mbedtls_havege_state *hs = (mbedtls_havege_state *) data;
be_bryan 0:b74591d5ab33 234 *olen = 0;
be_bryan 0:b74591d5ab33 235
be_bryan 0:b74591d5ab33 236 if( mbedtls_havege_random( hs, output, len ) != 0 )
be_bryan 0:b74591d5ab33 237 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
be_bryan 0:b74591d5ab33 238
be_bryan 0:b74591d5ab33 239 *olen = len;
be_bryan 0:b74591d5ab33 240
be_bryan 0:b74591d5ab33 241 return( 0 );
be_bryan 0:b74591d5ab33 242 }
be_bryan 0:b74591d5ab33 243 #endif /* MBEDTLS_HAVEGE_C */
be_bryan 0:b74591d5ab33 244
be_bryan 0:b74591d5ab33 245 #if defined(MBEDTLS_ENTROPY_NV_SEED)
be_bryan 0:b74591d5ab33 246 int mbedtls_nv_seed_poll( void *data,
be_bryan 0:b74591d5ab33 247 unsigned char *output, size_t len, size_t *olen )
be_bryan 0:b74591d5ab33 248 {
be_bryan 0:b74591d5ab33 249 unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
be_bryan 0:b74591d5ab33 250 size_t use_len = MBEDTLS_ENTROPY_BLOCK_SIZE;
be_bryan 0:b74591d5ab33 251 ((void) data);
be_bryan 0:b74591d5ab33 252
be_bryan 0:b74591d5ab33 253 memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
be_bryan 0:b74591d5ab33 254
be_bryan 0:b74591d5ab33 255 if( mbedtls_nv_seed_read( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 )
be_bryan 0:b74591d5ab33 256 return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
be_bryan 0:b74591d5ab33 257
be_bryan 0:b74591d5ab33 258 if( len < use_len )
be_bryan 0:b74591d5ab33 259 use_len = len;
be_bryan 0:b74591d5ab33 260
be_bryan 0:b74591d5ab33 261 memcpy( output, buf, use_len );
be_bryan 0:b74591d5ab33 262 *olen = use_len;
be_bryan 0:b74591d5ab33 263
be_bryan 0:b74591d5ab33 264 return( 0 );
be_bryan 0:b74591d5ab33 265 }
be_bryan 0:b74591d5ab33 266 #endif /* MBEDTLS_ENTROPY_NV_SEED */
be_bryan 0:b74591d5ab33 267
be_bryan 0:b74591d5ab33 268 #endif /* MBEDTLS_ENTROPY_C */